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Syndrome X (Microvascular Angina)


Ranya N. Sweis

, MD, MS, Northwestern University Feinberg School of Medicine;

Arif Jivan

, MD, PhD, Northwestern University Feinberg School of Medicine

Last full review/revision Jul 2020| Content last modified Jul 2020
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Syndrome X is cardiac microvascular dysfunction or constriction causing angina in patients with normal epicardial coronary arteries on angiography.

Patients with cardiac syndrome X have

  • Typical angina that is relieved by rest or nitroglycerin

  • Normal coronary arteriograms (eg, no atherosclerosis, embolism, or inducible arterial spasm)

Some of these patients have ischemia detected during stress testing; others do not. In some patients, the cause of ischemia seems to be reflex intramyocardial coronary constriction and reduced coronary flow reserve. Other patients have microvascular dysfunction within the myocardium: The abnormal vessels do not dilate in response to exercise or other cardiovascular stressors; sensitivity to cardiac pain may also be increased.

This disorder should not be confused with variant angina due to epicardial coronary spasm or with another disorder also called syndrome X, which refers to the metabolic syndrome.

Prognosis is better than for patients with demonstrable coronary artery disease, although symptoms of ischemia may recur for years.

The mainstay of treatment is controlling risk factors with lipid lowering therapy and glycemic control. In many patients, traditional anti-ischemic treatment, including beta-blockers and calcium channel blockers, helps to relieve symptoms (1).

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